Design On And Realizing User-Oriented Expert System For Hydraulic System Fault Diagnosis In Agricultural Machine

With the deveIopment of hydraulic technology, hydraulic system and hydraulicequipment are more complicated, hydraulic technology is more widely and morecomp1icatedly used in agricultural machine and their malfunction is more difficu1t to bedetected. Fault diagnosis of hydraulic system is not as apt to be observed as that of themechanical equipmeflt or is not as easy to be detected as that of electric equipmeflt bymu1tipurpose meter or other meters. Flux meter gage and pressure gage can't meet the needof fault diagnosis for hydraulic system because its working medium and workingcomponents are hiding inside the sealed vessel. At the same time hydraulic system inagricultural machine is apt to have malfunction because the users operate by mistake,overloading, bad working environment or aging. At present, the administration andmaintenance of hydraulic system in agricultural machine are very weak. The accumulationof the original fauIt record and the historicaI fault record is neglected. The theoreticalsummary of the diagnostic experience is neglected. Most of the experience is not tUrnedinto systematic written materials that make the diagnosis and maintenance have littlesystematic science in them. How to excavate, arrange and take the advantage of theexperience of the experts to make efficieflt diagnosis is imperative fOr us now.This thesis summarizes the fault histories of major hydraulic components and commonagricultural mechanical hydraulic system, builds knowledge database, stUdies on theoff line expert system for fault diagnosis of hydraulic system in agricultUral machine andmakes a expert system compiled in Visual BASIC fOr hydraulic fault including systemdiagnosis, components diagnosis and expert diagnosis. System diagnosis and componentSdiagnosis can query the fault cause or fault place according to the visible fault phenomenaand can query the solving methods according to the cause and the place. Expert systemdiagnosis adopts man-computer dialog pIatform, producing method, fault tree analysis andfOrward chaining. The user of hydrauIic equipment can eliminate the malfunction by thediagnosis of the software according to the visible phenomena. Because this systemaccumulates a good deal of fault message of hydraulic system in agricultUral machine, it hashighly value for users. It begins to realize that expert system is used in many hydrauiicsystem and components.This thesis provides the base for the further stUdying on expert system of hydraulic faultdiagnosis and enhances the efficiency and accuracy for hydraulic fault diagnosis inagricultural machine. It is significant to improve the efficiency of using hydraulic system in1lagricultural machine.Master Candidate: Chi Yuan Major: Agricultural Mechanization Supervisor: Associate Prof. Jin Yingzi...